Question: $ \lim_{x\to -1}(6x^2+5x-1)=$
$6x^2+5x-1$ defines a polynomial function. Polynomial functions are continuous across their entire domain, and their domain is all real numbers. In other words, for any polynomial $p$ and any possible input $c$, we know that this equality holds: $\lim_{x\to c}p(x)=p(c)$ Therefore, in order to find $ \lim_{x\to -1}(6x^2+5x-1)$, we can simply evaluate $(6x^2+5x-1)$ at $x=-1$. $\begin{aligned} &\phantom{=}6x^2+5x-1 \\\\ &=6(-1)^2+5(-1)-1 \gray{\text{Substitute }x=-1} \\\\ &=6-5-1 \\\\ &=0 \end{aligned}$ In conclusion, $ \lim_{x\to -1}(6x^2+5x-1)=0$.